] 893.] GElflTALIA OP BRITISH B.AJtTHWOEMS. 321 



accessory gland are the presence, in the latter, o£ several multi- 

 nucleate masses of protoplasm, whose nuclei are smaller than those 

 of the surroundiug cells and are arranged around the periphery of 

 this mass of protoplasm (fig. 3 6). These masses closely resemble 

 the mulberry stage in the development of the spermatozoa, as seen 

 in the seminal vesicles. Moreover, one observed two masses of 

 darkly staining bodies composed of elongated rods (fig. 3 c), some- 

 what bent on themselves, ^hich had all the appearance of nearly 

 ripe sperm bundles, although, owing to their being buried up 

 amongst a mass of cells, it was impossible to make out any flagella 

 in relation to them. 



The general structure of this body and the presence in it of 

 undoubted spermatozoa prove, I think, that it is to be regarded 

 as an over-developed testis, which, having no seminal vesicles 

 (receptacula seminis of Beddard ^) into which to discharge its 

 developing spermatozoa, has retained some of them, at any rate, 

 within its substance until they have become fully developed. 



The presence of a third testis is interesting as, except for a 

 description of Perrier's ", no one has, I believe, ever recorded the 

 presence of additional testes in the Oligochseta '. With regard to 

 Perrier's case, one cannot doubt for a moment, on referring to his 

 figures, that Vejdovsky * is right in saying that " Perrier's testes 

 are in reality the seminal vesicles." If this be the case, then 

 Allolohophora is the first Oligochaete proved to occasionally possess 

 three pairs of testes. This is not the only specimen having this 

 peculiarity, as I have since found two other abnormal foi-ms of 

 A. longa in which additional testes were present on the posterior 

 face of the 11/12 mesentery. 



Further, when we remember that this testis is developed in 

 exactly the same place as that in which I have described an undoubted 

 ovary in another individual {I. c. plate xiii. fig. 1, ov^), we have 

 further confirmation for the belief that the male and female genital 

 glands in the Oligochseta, at any rate, are homologous structures 

 and may be developed from the same tissue and in the same situa- 

 tion. 



Of the left half of the body, longitudinal sections were made so as 

 to pass through the testes, 1 he accessorygland, the ovary, and the seg- 

 ments immediately following (Plate XXIV. fig. 1). On examining 

 the accessory gland in section one immediately noticed, in addition 

 to the general mass of small cells already described, one or two 

 colossal cells (not all visible in the same section), and several 

 moderate-sized ones situated on its dorsal surface (fig. 4). Detailed 



' This term is not altogether a liappy one, as the older Helminthologists 

 applied it with perfect justice to the spermathecse. Its application to the 

 seminal vesicles, although expressing their imdoubted homology with the 

 receptacula ovorum, is apt to cause confusion. 



^ "Recherehes p. serv. a I'hist. d. Lumbriciens terrestres," Nouv. Archiv. d. 

 Mus. d'Hist. Nat. Paris, torn, viii., 1872. 



=* Bergh, Zeitschr. f. wiss. Zool. Ed. xliv. 1886, p. 308 (footnote), says " abnor- 

 mally placed additional testes are never found." 



* Syst. d. Oligochaeten, p. 135. 



